Don’t Compromise Your Oscilloscope Measurements by Selecting the Wrong Probe

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Selecting the correct probe for your oscilloscope measurements is very important but should not be difficult. The following is a list of probe parameters you should consider when selecting a probe for any given measurement.

 

 

Attenuation

Choose the attenuation ratio of the probe (1:1, 10:1, 100:1, 1000:1) to match the test signal amplitude to the oscilloscope’s vertical sensitivity range.

 

Bandwidth (BW)

The probe’s rated bandwidth should match the oscilloscope and be adequate for the test signal. However, at higher frequencies, grounded lead inductance input capacitance often influences system performance more than probe bandwidth does.

 

Input Resistance (R_in)

The probe’s input resistance must match the oscilloscope’s input impedance to avoid a characteristic impedance mismatch. It also must be appropriate to the test signal to avoid excessive loading.

 

Input Capacitance (C_in)

Excessive input capacitance (sometimes called tip capacitance) will slow down the system’s pulse response. Usually the least input capacitance possible is best.

 

Maximum Input Voltage (V_max)

To ensure user safety, help protect the oscilloscope input from destructive voltage, and avoid damage to the probe, select one that is rated for a higher voltage than the signal you intend to test.

 

Probe Compensation Range

Most probes have a specification that lists the oscilloscope input capacitance range over which they can be used. When choosing a probe, be sure that the oscilloscope’s input capacitance lies within the probe’s compensation range or you will not be able to adjust the probe to achieve a correctly compensated square wave signal.

Most oscilloscopes have 1MΩ input resistance. This input resistance is in parallel with the input (shunt) capacitance. Normally, high frequency probes with attenuation factors greater than 1:1 have adjustable compensation networks built into them. Adjusting this compensation network provides the best possible frequency linearity over the oscilloscope’s designed frequency range.

Properly Compensated	Over Compensated
Under Compensated

Probe Tip Form Factor

Your probe must make a reliable connection to the test point, and you may want it to grab it. Generally, this requires a small and light probe and a tip or grabber that is compatible with the test point. SMT and fine pitch geometries make this issue especially critical.

 

Probe Interface

Most Agilent oscilloscopes offer either BNC type of probe interface with a probe attenuation sense, or the Auto Probe interface which automatically sets probe attenuation and provides power for active probes.

 

Recommended Agilent Scope Probes for 5000/6000/8000 Series Scopes

• 1156A - 1.5GHz single-ended active probe
• 1130A - 1.5GHz differential active probe
• 1147A - 50MHz/15A current probe
• 10070C - 1:1 passive probe
• 10076A - 100:1 passive probe
• 10073C - 10:1 passive probe for ≥300MHz models
• 10074C - 10:1 passive probe for 100MHz models
• N2863A - 10:1 passive probe for 100MHz - 5000 Series

 

Recommended Agilent Scope Probes for 3000 Series Scopes

• N2772A - 20MHz differential probe
• 1146A - 100kHz/100A current probe
• 10070C - 1:1 passive probe
• 10076A - 100:1 passive probe
• N2862A - 10:1 passive probe for 60MHz - 150MHz models
• N2863A - 10:1 passive probe for 200MHz models

 

 

10070C Passive Probe, 1:1, 20MHz, 1.5m

The Agilent 10070C 20MHz passive probe is a great choice if you are looking for high quality at a very reasonable price. This general purpose probe is designed specifically to give you optimal performance with your 6000 Series and 54620 Series oscilloscopes. Ruggedized for general purpose measurements, the 10070C features a durable cable and a solid stainless steel probe body encased with a hard, fracture-resistant plastic.

FEATURES General purpose retractable hook tip - hooks onto wires and test points for hands-free probing Ground bayonet - provides short, flexible ground lead for high frequency measurements General purpose alligator clip ground lead - allows for versatile grounding Color tags (2 tags in each color: orange, white, blue and green) - by placing tags at both ends of the probe cable, you can quickly identify your probes Rise time (calculated): <17.5ns Input resistance: 1MOhm; (when terminated into 1MOhm) Designed for optimal performance with your Agilent 54620 series scope Input capacitance: 70pF (approximate)

 

10073C Passive Probe, 10:1, 500MHz

The Agilent 10073C passive probe is our most rugged 500MHz probe. With a 10:1 attenuation ratio and high 2.2Mohm input impedance, it is ideal as a general purpose, high bandwidth passive probe for the Agilent 300MHz - 1GHz 6000 series, and 8000 series oscilloscopes. The probe identification feature automatically configures the oscilloscope for the probe attenuation.

The following accessories are included: retractable hook tip; orange, white, blue and green identification tags; ground bayonet, IC probing tip, adjustment tool and an alligator clip ground lead.

FEATURES Bandwidth: 500MHz System risetime (calculated): <700ps Attenuation Ratio: 10:1 Input resistance: 2.2MΩ (when terminated into 1MOhm) Input capacitance: ~12pF Maximum input (dc + peak ac): 500V CAT I (mains isolated) 300V CAT II (post receptacle mains) Compensation range: 6-15pF

 

10074C Passive Probe, 10:1, 150MHz

The Agilent 10074C 150MHz passive probe is a great choice if you are looking for high quality at a very reasonable price. This general purpose probe is designed specifically to give you optimal performance with your 6000 Series 100MHz models and 54620 Series oscilloscopes. Ruggedized for general purpose measurements, the 10074C features a durable cable and a solid stainless steel probe body encased with a hard, fracture-resistant plastic. General purpose retractable hook tip - hooks onto wires and test points for hands-free probing Ground bayonet - provides short, flexible ground lead for high-frequency measurements general purpose alligator clip ground lead - allows for versatile grounding Color tags (2 tags in each color: orange, white, blue and green) - by placing tags at both ends of the probe cable, you can quickly identify your probes.

FEATURES General purpose retractable hook tip - hooks onto wires and test points for hands-free probing Ground bayonet - provides short, flexible ground lead for high-frequency measurements General purpose alligator clip ground lead - allows for versatile grounding Color tags (2 tags in each color: orange, white, blue and green) Risetime (calculated): <2.33ns Input resistance: 10MOhm; (when terminated into 1MOhm;) Input capacitance: 15pF (approximate) Mains isolated: 500V CAT I Post receptacle mains: 400V CAT II Compensation range: 9-17pF

 

10076A 100:1, 4kV, 250MHz High Voltage Probe

The Agilent 10076A 4kV, 100:1 passive probe gives you the voltage and bandwidth you need for making high voltage measurements. Its compact design makes it easier to probe today's small power electronics components and its rugged construction means it can withstand rough handling without breaking.

FEATURES Bandwidth (-3dB): 250MHz Rise time (calculated): <1.4ns Attenuation ratio: 100:1 Input resistance: 66.7Mohm (when terminated into 1Mohm) Input capacitance: 3pF (approximate) Compensation range: 7-20pF Maximum input: 4000Vpk Length: 1.8m

 

1130A 1.5GHz Differential Probe Amp- No Probe Head

For high speed differential or single ended probing in embedded designs, the InfiniiMax 1.5GHz 1130A differential probe amplifier is a perfect complement to the Infiniium Series and 6000 Series 300MHz - 1GHz oscilloscopes. Its extremely low input capacitance high common mode rejection and the patented resistor probe tip technology provide ultra low loading of the DUT and superior signal fidelity. The E2675A differential browser kit (ordered separately) is recommended for the 1130A with its variable spacing between probe tips with full z-axis compliance, which improves the usability/versatility of the probe. Also available are the E2669A differential or E2668A single ended connectivity kits (ordered separately) that contain a variety of connectivity probe heads and accessories.

FEATURES Bandwidth: 1.5GHz Range: Dynamic Range: +/- 2.5V DC Offset Range: +/- 12V when probing single ended Maximum Input Voltage: 30V peak Input Impedance: Differential Input R: 50kOhm Differential Input C: 0.27-0.34pF Single Ended Input R: 25kOhm Single Ended Input C: 0.44-0.67pF

 

1146A 100kHz /100A AC/DC Current Probe

This AC/DC current probe provides accurate display and measurement of currents from 100mA to 100A RMS, DC to 100kHz, without breaking the circuit. The Agilent 1146A uses Hall-effect technology to measure AC and DC signals. It is compatible with all Agilent oscilloscopes and any scope with 0.2 to 0.5V/div sensitivity, a minimum input impedance of 1MΩ and a BNC input.

FEATURES Frequency range: DC to 100kHz (-3dB with current derating) Current range, 1mV/A: 100mA to 10A peak 10 mV/A: 1 to 100 A peak 10mV/A ac/dc: 1000mV peak AC current accuracy, 100mV/A (50mV to 10A peak) - 3% of reading ≥50A 10mV/A (500mA to 40 A peak) - 4% of reading ≥50 mA 10mV/A (40A to 100A peak) - 15% max at 100A Working voltage: 600V max Battery: 9V alkaline

 

1147A 50MHz/15A AC/DC Current Probe

The Agilent 1147A is a wide bandwidth, active current probe for 6000 Series 300MHz - 1GHz and Infiniium Series 600MHz - 1GHz oscilloscopes. The probe features flat bandwidth (DC-50MHz), low noise (<2.5mA RMS) and low circuit insertion loss. The 1147A is ideal for capturing transient current signals such as those found in motor controllers, in switching power supplies, inverters and current amplifiers driving inductive loads.

FEATURES Wide bandwidth: DC to 50MHz High S/N ratio, low current measurement capability 15A continuous, 50A peak dc + ac pulse current Easy protect function at excessive input Demagnetizing switch to remove any residual magnetism that builds up in the magnetic core AutoProbe interface compatible

 

1156A Active Probe, 1.5GHz

The Agilent 1156A, 1157A, and 1158A family of active probes offers R & D engineers the performance they need to probe small geometries in hard-to-reach areas on the DUT. These probes were designed specifically for the Infiniium Series, and 6000 Series 300MHz - 1GHz oscilloscopes.

As the speeds in your design increase, you may notice more overshoot, ringing, and other perturbations when connecting an oscilloscope probe. Probes form a resonant circuit where they connect to the device. If this resonance is within the bandwidth of the oscilloscope probe you are using, it will be difficult to determine if the measurement perturbations are due to your circuit or the probe.

Agilent is the only company that has overcome the resonance formed by the connection of a probe to a device. The Agilent 1156/7/8A probes optimize performance to make your job easier.

FEATURES Bandwidth: 1.5 GHz Range: DC Offset Range: +/- 15V Dynamic Range: 5V peak-to-peak Input Impedance: Input R: 100kOhm Input C: 0.8pF Connectivity: AutoProbe interface compatible

 

N2772A 20MHz Differential Probe

Use the Agilent N2772A Differential Probe with any Agilent oscilloscope to safely measure floating circuits with the oscilloscope grounded. With 20MHz bandwidth and switchable attenuation of 20:1 and 200:1, it provides the versatility for a broad range of applications including high voltage circuits, motor speed controls, power supply design and electronic high power converters.

This probe requires a 9V battery or Agilent N2773A power supply.

FEATURES Measure up to 600V CAT III 20:1 and 200:1 switchable attenuation Supplied with a retractable hook, sharp probe tips and alligator clips Bandwidth: 20MHz Rise time: 17.5ns Attenuation ratios: 20:1 and 200:1, selectable via switch on probe High CMRR, 80dB at 60Hz, 50dB at 1MHz Input impedance between inputs: 10Mohm, 5pF

 

N2862A Passive Probe, 10:1, 150MHz

The Agilent N2862A low cost passive probe provides a 10:1 attenuation and features a high input resistance of 10MΩ. The probe can be adjusted for low frequency compensation and high frequency compensation.

FEATURES Cable length 1.2m Bandwidth DC to 150MHz Risetime 2.33ns Attenuation ratio 10:1 Input resistance 10MΩ (when terminated into 1 MΩ) Input capacitance ≈12pF Maximum input 300V RMS

 

N2863A Passive Probe, 10:1, 300MHz

The Agilent N2863A low cost passive probe provides a 10:1 attenuation and features a high input resistance of 10MΩ. The probe can be adjusted for low frequency compensation and high frequency compensation.

FEATURES Cable length 1.2m Bandwidth DC to 300MHz Risetime 1.16ns Attenuation ratio 10:1 Input resistance 10MΩ (when terminated into 1MΩ) Input capacitance ≈12pF Maximum input 300V RMS

 

 

 Featured Products

Part Number		Description	Data Sheet	App. Notes
10070C		Passive Probe, 1:1, 20MHz
10073C		10:1 Passive Probe for = 300MHz Models
10074C		10:1 Passive Probe for 100MHz Models
10076A		100:1 4KV Passive Probe
1130A		InfiniiMax 1.5GHz Probe
1146A		100kHz/100A AC/DC Current Probe
1147A		50MHz/15A AC/DC Current Probe
1156A		Active Probe, 1.5GHz
N2772A		20MHz Differential Probe
N2862A		10:1 Passive Probe for 60MHz -150MHz Models
N2863A		10:1 Passive Probe for 200MHz Models

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